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Document Type

Thesis - University Access Only

Award Date

2015

Degree Name

Master of Science (MS)

Department

Mechanical Engineering

First Advisor

Zhong Hu

Abstract

There has been a huge interest to characterize mechanical properties in a micro/nano-scale, which is simply faster than traditional macro scale testing and also able to utilize the modern applications of depth-sensing indentation tests. Nanoindentation using a cylindrical flat tip indenter comes with some unique features which makes it a reliable source to find material’s yield strength as well as other mechanical properties. This work presents a quantitative investigation to the effect of angular misalignment on the outputs obtained from nanoindentation testing by a cylindrical flat tip indenter coupled with computer modeling. A nanoindentation 3-D symmetric solid model was built and FEA modeling was conducted. This computer modeling offered the characterization of material’s elastic-plastic properties based on the hemi-spherical stressstrain distribution assumption of an elastic plastic indentation. Low carbon steel AISI 1018 was selected as sample material and material properties were taken from the tensile test. The modeling was done by considering the angle of misalignment ranging from 0o to 1o in order to find the influences of misalignment angle on the elastic-plastic properties’ characterization and was verified by associated experimental results. Elastic modulus, hardness values were estimated and also 0.1% and 0.2% yield strengths were extracted by identifying the corresponding load points of load-depth curve considering a correction factor k and validated by nanoindentation tests.

Library of Congress Subject Headings

Materials -- Mechanical properties Materials -- Elastic properties Nanotechnology

Description

Includes bibliographical references (pages 77-83)

Format

application/pdf

Number of Pages

94

Publisher

South Dakota State University

Rights

In Copyright - Non-Commercial Use Permitted
http://rightsstatements.org/vocab/InC-NC/1.0/

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